Here, \(\mathbf {P}\)  is the momentum outgoing meson (meson \(B\)  or meson \(C\) ). \(M_A\)  is the mass of meson \(A\) . \({L}\)  and \({S}\)  denote the relative orbital angular and total spin momentum between meson \(B\)  and \(C\) , respectively. \(M^{LS}\)  denotes the partial wave amplitude and is related to the helicity amplitude \(M^{M_{J_A}M_{J_B}M_{J_C}}\)  according to Jacob-Wick formula [1]}. In the CM frame, the specific form of \(M^{M_{J_A}M_{J_B}M_{J_C}}\)  can be written as
\(\begin{split}&M^{M_{J_A}M_{J_B}M_{J_C}}({P})\nonumber \\&=\gamma \sqrt{8E_AE_BE_C}\sum \limits _{M_{L_A},M_{S_A},M_{L_B},M_{S_B},M_{L_C},M_{S_C}}\langle L_AM_{L_A}S_AM_{S_A}|J_AM_{J_A}\rangle \;\nonumber \\&\quad \times \langle L_BM_{L_B}S_BM_{S_B}|J_BM_{J_B}\rangle \langle L_CM_{L_C}S_CM_{S_C}|J_CM_{J_C}\rangle \\&\quad \times \langle 1m1-m|00\rangle \;\langle \chi _{S_BM_{S_B}}^{14}\chi _{S_CM_{S_C}}^{32}|\chi _{S_AM_{S_A}}^{12}\chi _{1-m}^{34}\rangle \\&\quad \times \bigg [\langle \phi _B^{14}\phi _C^{32}|\phi _A^{12}\phi _0^{34}\rangle I({P},m_2,m_1,m_3)\\&\quad +(-1)^{1+S_A+S_B+S_C}\langle \phi _B^{32}\phi _C^{14}|\phi _A^{12}\phi _0^{34}\rangle I({-P},m_2,m_1,m_3)\bigg ],\end{split}\) 
